Is Creatine the Only Supplement You Need?

The supplement industry generates over $50 billion annually in the United States alone. The average gym-goer might spend $100 to $300 per month on various powders, pills, and proprietary blends. Against this backdrop, a provocative question deserves an honest answer: if you could only take one supplement, should it be creatine? And if so, does anything else actually pass the evidence test?

The Supplement Evidence Hierarchy

Not all supplement evidence is equal. A useful hierarchy, adapted from evidence-based medicine principles, can be applied to sports supplements:

1. Unambiguous evidence: Multiple meta-analyses, hundreds of RCTs, consensus position statements from major scientific organizations. Effects are consistent, well-quantified, and independently replicated worldwide.
2. Strong evidence: Multiple RCTs with consistent results, at least one meta-analysis, and recognition by scientific bodies. Mechanistically well-understood.
3. Moderate evidence: Several RCTs with mostly positive but some mixed results. Mechanistically plausible. May lack large-scale replication or long-term data.
4. Emerging/weak evidence: A few small RCTs or primarily acute/mechanistic studies. Promising but not yet conclusive. Effect sizes may be inconsistent.
5. No credible evidence: Marketing claims only, contradicted by available research, or supported only by animal/in-vitro data not replicated in humans.

Where Creatine Sits

Creatine monohydrate is the only supplement that unambiguously occupies the top tier. The ISSN position stand (Kreider et al., 2017) reviewed over 500 peer-reviewed studies. The conclusion: creatine monohydrate is the most effective ergogenic nutritional supplement currently available for increasing high-intensity exercise capacity and lean body mass during training. The ACSM, EFSA, and virtually every sports nutrition textbook concur.

No other sports supplement has this level of evidence. That is not hyperbole. It is a straightforward assessment of the research record. Creatine has been studied in more contexts, more populations, more training paradigms, and with more consistent results than any competing ergogenic supplement.

The mechanism is direct, well-characterized at the molecular level, and does not depend on hormonal modulation, placebo effects, or poorly understood pathways. Phosphocreatine donates a phosphate group to ADP, regenerating ATP. More phosphocreatine in muscle means more ATP regeneration capacity during maximal efforts. This is biochemistry, not marketing.

What Else Passes the Evidence Test?

While creatine sits alone at the top, a small number of other supplements have legitimate evidence behind them.

Caffeine (Strong Evidence)

Caffeine is the most widely consumed psychoactive substance in the world, and its ergogenic effects are well-documented. Grgic et al. (2018) confirmed through meta-analysis that caffeine significantly improves muscle strength, muscle endurance, and power output. The ISSN position stand on caffeine (Goldstein et al., 2010) endorses it as an effective ergogenic aid. Caffeine works acutely (no loading required), is inexpensive, and has a well-understood mechanism (adenosine receptor antagonism, enhanced neural drive, reduced perceived exertion). However, caffeine is a stimulant with habituation effects and is already consumed by most people through coffee and tea, which somewhat diminishes its uniqueness as a "supplement."

Beta-Alanine (Strong Evidence for Specific Contexts)

Beta-alanine increases intramuscular carnosine, buffering hydrogen ions during sustained high-intensity exercise lasting 60 to 240 seconds. The ISSN position stand (Trexler et al., 2015) and meta-analyses (Hobson et al., 2012; Saunders et al., 2017) support its efficacy in this specific time domain. It does not improve maximal strength or short-burst performance in the way creatine does, but for athletes who need sustained anaerobic output, it is well-supported.

Protein Powder (Strong Evidence, But a Macronutrient)

Protein powder is technically a food supplement, not an ergogenic aid. It provides amino acids. Its benefit is in helping individuals reach daily protein targets (1.6 to 2.2 g/kg/day), which Morton et al. (2018) confirmed is sufficient to maximize resistance training-induced gains. Protein powder has no unique effect beyond what an equivalent amount of chicken, fish, eggs, or dairy provides. It is a convenience product.

Everything Else: The Drop-Off Is Steep

Beyond creatine, caffeine, beta-alanine, and protein, the evidence quality drops substantially. Citrulline malate shows promise but has a limited number of RCTs and inconsistent results. Ashwagandha has some positive findings but needs more replication. Betaine, HMB, and nitrate each have narrow or contested evidence. BCAAs, glutamine, testosterone boosters, and most proprietary blends have no compelling evidence of benefit in well-nourished individuals.

The Case for Creatine as the Only Supplement

If you had to reduce your supplement regimen to one product, creatine is the rational choice. Here is why:

• Unique mechanism: Creatine provides a physiological effect that food cannot practically replicate. You would need approximately 1 to 2 pounds of raw red meat daily to match the intramuscular creatine concentrations achieved through supplementation. No other supplement provides a comparably unique effect.
• Breadth of benefit: Creatine improves strength, lean mass, work capacity, and potentially cognitive function. Emerging evidence supports benefits for bone mineral density and neuroprotection. It is not a niche supplement.
• Cost: At $10 to $15 per month, creatine is the cheapest effective supplement on the market. The cost-to-benefit ratio is unmatched.
• Safety: Decades of research have identified no adverse effects in healthy individuals. Long-term studies up to five years confirm safety.
• Simplicity: 3 to 5 grams daily. No timing requirements. No cycling needed. No loading strictly necessary (though it accelerates saturation).

The Case Against Creatine as the ONLY Supplement

Being the best single supplement does not mean it is the only one worth taking. The argument against a creatine-only approach recognizes that different supplements address different limiting factors:

• If you cannot meet daily protein targets through food, protein powder serves a practical purpose creatine cannot.
• If you need acute alertness and focus for training, caffeine addresses that need where creatine does not.
• If your training involves sustained efforts in the 1 to 4 minute range, beta-alanine targets the carnosine buffering system that creatine does not touch.
• If your vitamin D levels are low (as they are in roughly 42% of American adults), a vitamin D supplement may be more impactful on general health than any ergogenic aid.

Verdict

Is creatine the only supplement you need? Almost. If you eat enough protein, train with adequate intensity, sleep well, and manage stress effectively, creatine is the single supplement most likely to improve your outcomes. It provides a unique physiological effect at the lowest cost of any effective supplement, supported by the largest body of evidence in sports nutrition.

A more precise answer: creatine is the only ergogenic supplement most people need. Beyond creatine, the next tier of evidence-supported supplements (caffeine, beta-alanine, protein powder) each serve specific, non-overlapping functions. But if you are spending $150 per month on supplements and not taking creatine, your priorities are inverted. Start with the one that has 500 studies behind it, costs $10 a month, and has been called the most effective nutritional supplement available by every major sports nutrition organization. Build from there only if your budget, training demands, and dietary gaps justify it.